CVE-2025-20212Network attack vector

Authenticated service restart via uninitialized session variable

Published Apr 2, 2025 · Updated Apr 2, 2025

Denial of service in the AnyConnect VPN server in Cisco Meraki MX Firmware allows remote authenticated users to restart the service. During SSL VPN session establishment, the server uses an uninitialized variable when processing attacker-supplied attributes. Valid VPN credentials and enabled AnyConnect VPN are required; established sessions fail, and sustained requests block new connections until traffic stops.

CVSS severity7.7
High
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the AnyConnect VPN server in Cisco Meraki MX Firmware allows remote authenticated users to restart the service. During SSL VPN session establishment, the server uses an uninitialized variable when processing attacker-supplied attributes. Valid VPN credentials and enabled AnyConnect VPN are required; established sessions fail, and sustained requests block new connections until traffic stops.

The record

CVE
CVE-2025-20212
Published
Apr 2, 2025
Updated
Apr 2, 2025
Vendor
ClamAV
Product
Cisco Meraki MX Firmware
Classifications
CWE-457, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.2
  2. Affected versionversion=16.3
  3. Affected versionversion=16.4
  4. Affected versionversion=16.5
  5. Affected versionversion=16.6
  6. Affected versionversion=17.10
  7. Affected versionversion=17.3
  8. Affected versionversion=17.6
  9. Affected versionversion=17.7
  10. Affected versionversion=17.8
  11. Affected versionversion=17.9
  12. Affected versionversion=18.1
  13. Affected versionversion=18.2
  14. Affected versionversion=19.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ClamAV · Cisco Meraki MX Firmwareversion=16.2; version=16.3; version=16.4; version=16.5; version=16.6; version=17.10; version=17.3; version=17.6; version=17.7; version=17.8; version=17.9; version=18.1; version=18.2; version=19.1

Published CVSS scores

7.7Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-457Use of Uninitialized Variable
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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